JP5022067B2 - Power generation control method during idling charging of hybrid electric vehicle - Google Patents

Description

The present invention relates to a power generation control method during idling charging of a hybrid electric vehicle. More specifically, the power generation amount is adjusted according to a value calculated using a high altitude correction coefficient so that an appropriate load of the engine is maintained. In order to improve the noise and vibration due to the power generation load amount, the power generation load and the RPM are controlled according to whether the air conditioner is operated and the position of the shift stage, and when the actual RPM falls below the reference value compared to the target charge RPM, The present invention relates to a power generation control method during idling charging of a hybrid electric vehicle that inputs correction values and corrects RPM.

  In general, a hybrid vehicle in a broad sense means that the vehicle is driven by efficiently combining two or more different power sources, but in most cases, an engine and a battery that use fuel to obtain driving force. This means a vehicle that obtains a driving force by an electric motor that is driven by the electric power, and is called a hybrid electric vehicle (HEV).

  Recently, research on hybrid electric vehicles has been conducted more actively in response to the trend of the era of improving fuel efficiency and demanding more environmentally friendly products. Although hybrid electric vehicles can form a variety of structures using an engine and an electric motor as power sources, most vehicles studied up to now have adopted one of a parallel type and a series type.

  Among them, the parallel type has the disadvantage that the engine charges the battery, but directly drives the vehicle together with the electric motor, and the structure is relatively more complicated than the serial type and the control logic becomes complicated. However, since the mechanical energy of the engine and the electric energy of the battery can be used at the same time, the structure is widely adopted for passenger cars and the like due to the advantage of energy efficiency.

  In particular, since the optimum operating region of the engine and the electric motor is used, not only the fuel efficiency of the entire drive system is improved, but also the energy is recovered by the electric motor at the time of braking, so that efficient energy use is possible. The hybrid electric vehicle is equipped with a vehicle control unit (HCU) in charge of overall vehicle control, and also includes a control device for each device constituting the system.

  For example, an engine control unit (Engine Control Unit, ECU) that controls overall engine operation, a motor control unit (Motor Control Unit, MCU) that controls overall electric motor operation, a transmission control unit (Transmission Control). Unit, TCU), a battery management system (BMS) for controlling the operation of the battery, an air conditioner controller (Full Auto Temperature Controller, FATC) for controlling the room temperature, and the like.

Such a control device is connected by a high-speed CAN communication line centering on a vehicle control device which is a host control device, and the host control device transmits a command to the lower control device while transmitting information between the control devices. ing. Further, as the hybrid electric vehicle is a high voltage battery that provides power for driving the electric motor (main battery) is mounted, a high voltage battery in the vehicle operation is to supply the necessary power while repeatedly charging and discharging It has become.

  During motor assistance, the high-voltage battery supplies (discharges) electrical energy, and stores (charges) electrical energy during regenerative braking or when the engine is driven. At this time, the BMS is in the battery charge state (State of Charge; SOC) Then, the available charge power, available discharge power, etc. are transferred to the HCU and MCU to manage the safety and life of the battery.

  On the other hand, when the hybrid electric vehicle continuously climbs and travels in a mountainous area, the motor assist is maintained, thereby reducing the SOC of the high voltage battery. At this time, the SOC decreases to an optimum level that can be controlled by the high voltage battery, but power generation is performed to prevent the SOC from decreasing, and motor assist and charging are repeated according to the SOC charge level. When the SOC reaches a certain level, power generation is always performed to recover the SOC except for a minimum case for SOC recovery. Therefore, power corresponding to the maximum capacity of the engine is supplied to the high voltage battery in order to make the SOC recovery as fast as possible. Even in the idling state when the vehicle is stopped, power is still generated and the SOC is recovered. In this case, the power corresponding to the maximum value of the idling torque is used for power generation.

  However, the conventional method has the following problems. The engine transmits the necessary power of the motor in advance through CAN communication, and the motor generates the necessary power. The engine controls the power with a margin on flat ground. That is, power can be transmitted with a sufficient margin for supply even when an air conditioner or other load is applied. The problem is in the case of high altitude traveling, but engine power is not generated as in flat ground during high altitude traveling.

For example, a large amount of power is required when an air conditioner is attached. In this case, if the power generated on a flat ground is applied as it is, the allowable engine power will be exceeded, causing engine stall (hereinafter, engine stall). End up. At high altitudes, when the air volume becomes lean, the atmospheric pressure drops and the engine power decreases. At this time, if the power is generated like on a flat ground, a load higher than the engine output is applied and there is a danger of engine stall. Therefore, when the high-voltage battery is charged in the hybrid electric vehicle, it is necessary to set the power generation amount within the engine allowable capacity, and it is necessary to improve the power generation amount setting and the charge control particularly in the highland.
JP 2003-161364 A

The present invention I der been made to solve the above SL problem, that improved SOC management capabilities in mountainous terrain often condition, to prevent deterioration of the fuel consumption / exhaust performance due to excessive charge in advance The purpose is to provide a power generation control method during idling charging of a hybrid electric vehicle that can effectively prevent engine stall.

The present invention has been made in order to achieve the above Symbol object is achieved by a vehicle control device (HCU) and the engine control unit (ECU) and the power generation control method during idling charging of the hybrid electric vehicle that is controlled by the current vehicle speed Is determined to be equal to or less than a preset idling charge allowable critical vehicle speed, and if the current vehicle speed is equal to or less than the idling charge allowable critical vehicle speed, it is determined whether the current SOC amount is equal to or less than the idling charge critical SOC. the method comprising, the case where the current SOC amount Ru der less idling charge critical SOC, whether air or is turned off in the on state (air conditioner operation existence), the position of the current gear, and by SOC weight The idling charging power amount is calculated through the setting map , and the target charging RPM is calculated based on the calculated charging power amount. And after the HCU obtains a difference value from the target RPM value from the input current RPM , the HCU calculates a power generation amount correction coefficient based on the difference value, and is attached to the engine. calculating a high altitude correction coefficient by the current atmospheric pressure of on the basis of the signal inputted from the ECU of pressure sensors, when the calculated highlands correction coefficient is less than the reference value, a correction coefficient and high altitude correction coefficient of the power generation amount Calculating the final charge power amount by sequentially multiplying the charge power amount, and the HCU finally calculates a target charge torque value that is a value based on the final charge power amount and the target charge RPM, The target charging torque value is transferred to the ECU, and the ECU controls the power generation load and the RPM according to the target charging RPM and the target charging torque value transferred from the HCU. And wherein the benzalkonium control the amount of power generation and battery charge by amount.

According to the power generation control method at the time of idling charging of the hybrid electric vehicle according to the present invention, the power generation amount is adjusted according to the value calculated using the high altitude correction coefficient so that the appropriate load of the engine is maintained. In order to improve noise and vibration, the power generation load and the RPM are controlled according to the availability of the air conditioner and the gear position, and when the actual RPM falls below the reference value compared with the target charge RPM, a correction value for the power generation amount is set. By inputting and correcting for RPM, the following effects can be obtained.

  Without adding a separate sensor, the atmospheric pressure sensor already installed in the vehicle is used to correct the altitude, improving the SOC management ability under conditions with a lot of mountainous terrain, and worsening fuel consumption and exhaust performance due to excessive charging. Can be prevented and engine stall can be effectively prevented. Further, since the power generation load and the RPM are controlled according to whether the air conditioner is operated and the position of the gear position, noise and vibration felt by the vehicle can be improved. Furthermore, it is possible to distribute the generated power and correct the RPM difference with respect to the high altitude correction, which can be effectively applied to the idling charging control.

Hereinafter, described in detail to the drawings refer for the embodiment of the power generation control method during idling charging of the hybrid electric vehicle according to the present invention.

  As mentioned in the prior art, in a hybrid electric vehicle that uses an engine and a motor as driving sources, the amount of charge of a high-voltage battery that supplies electric power to the motor, that is, the high driving power of the engine is used to recover the SOC. The battery is charged, but when the engine is at high altitude and the air volume becomes lean, the atmospheric pressure decreases and the output decreases. At this time, if the power is generated in the same manner as the flat ground, a load higher than the engine output is applied, and there is a danger of engine stall.

In this embodiment , in order to avoid the above situation, the vehicle control device (hybrid control device, hereinafter referred to as HCU) is an atmospheric pressure attached to the engine output from the engine control device (hereinafter referred to as ECU). based on the sensor signal, calculates a highland correction coefficient due to the current atmospheric pressure, when the calculated highlands correction coefficient is below standard values, and adjust the power generation amount so that the proper load of the engine is maintained.

In this embodiment , in order to improve noise and vibration due to the power generation load, the power generation load and the RPM are adjusted according to the position of the air conditioner on and the shift stages D, R, L, P, N, and the current When the RPM, that is, the actual RPM falls below the reference value compared with the target RPM, a correction value for the power generation amount is input to correct the RPM.

FIG. 1 is a flowchart illustrating a target charging RPM and charging torque calculation process based on high altitude correction and a power generation load amount in a power generation control process according to the present embodiment . First, the HCU determines whether the current state satisfies the idling charging condition. That is, the HCU determines whether the current state is a state where idling charging is possible, and if idling charging is possible, the current vehicle speed is a state where idling charging is permitted, that is, a preset allowable criticality. It is determined whether the vehicle speed is below the vehicle speed.

Here, if the vehicle speed allows idling charging, it is determined whether the current SOC amount corresponds to the idling SOC. If the SOC quantity is determined to be the idle SOC is below a set value, the load operation whether, for example, to determine the air conditioner operation whether the current air conditioner operation whether the position of the current gear, and idling by SOC weight The charging power amount is calculated through the setting map.

Ri far shown in FIG. 1, the current air conditioner operation whether time, i.e., when the air conditioning is on or off, is the D, R, L stage when a is P, N-stage position of current gear The charging power amount is calculated based on the current gear position and the SOC amount. Next, the charging RPM is calculated based on the charging power amount calculated according to each situation. First, the charging RPM is calculated based on whether or not the air conditioner is operated and the position of the gear position.

Ri far shown in FIG. 1, the current air conditioner operation existence, i.e., when the air conditioning is on or off, the current position of the gear is P, when N stages and D, R, when a L-stage The charge RPM according to the current gear position and the SOC amount is calculated. Thereafter, the charging RPM calculated as described above is set as the target charging RPM, and this is transferred to the ECU.

On the other hand, in this embodiment , the HCU receives an input of the current RPM, calculates a difference value from the previously obtained target charge RPM value, calculates a power generation amount correction coefficient based on the difference value, or from the ECU calculating a high altitude correction factor based on the signal of the atmospheric pressure sensor is input, the charging power amount during idling, to calculate the final charge power amount by multiplying the correction coefficient and high altitude correction coefficient power generation amount in order. The HCU controls the power generation amount and the battery charge amount according to the final charge power amount.

Further, the target charging torque value, which is a value based on the final charging power amount and the target charging RPM calculated as described above , is finally calculated, and the calculated target charging torque value is transferred to the ECU, which transfers the ECU from the HCU. The power generation load and the RPM are controlled according to the target charge RPM and the target charge torque.

In this way, in the present invention, the power generation amount is adjusted by the value calculated using the high altitude correction coefficient so that the appropriate load of the engine is maintained, and in order to improve noise and vibration due to the power generation load amount, the air conditioner The power generation load and the RPM are controlled in accordance with the presence / absence of the operation and the position of the shift stage, and when the actual RPM falls below the reference value compared with the target charge RPM, a correction value for the power generation amount is input to correct the RPM. .

In the power generation control method according to the present invention, it is a flow chart showing a target charging RPM and charging torque calculation process by high altitude correction and power generation load amount.

Claims (1)

A power generation control method during idling charging of a hybrid electric vehicle controlled by a vehicle control unit (HCU) and an engine control unit (ECU) ,
Determining whether the current vehicle speed is less than or equal to a preset idling charge allowable critical vehicle speed;
Determining whether the current SOC amount is equal to or lower than the idling charge critical SOC if the current vehicle speed is equal to or lower than the idling charge allowable critical vehicle speed;
If SOC of the currently Ru der less idling charge critical SOC, whether air or is turned off in the on state (air conditioner operation existence), the position of the current gear, and the idling charge power amount by the SOC quantity calculating a target charge RPM based on the charge amount of power calculated through setting map, which is calculated,
After the HCU obtains a difference value from the target charge RPM value from the received current RPM, the HCU calculates a correction coefficient for the power generation amount based on the difference value, and from the ECU of the atmospheric pressure sensor attached to the engine Based on the input signal, a high altitude correction coefficient according to the current atmospheric pressure state is calculated, and when the calculated high altitude correction coefficient is equal to or less than a reference value, the power generation amount correction coefficient and the high altitude correction coefficient are sequentially calculated as the charge power amount. comprises the steps of calculating the final charging power amount by multiplying,
The HCU finally calculates a target charging torque value, which is a value based on the final charging power amount and the target charging RPM, the target charging torque value is transferred to the ECU, and the ECU transfers the target charging RPM transferred from the HCU and the target charging torque. It controls the power generation load and RPM accordance charge torque values, HCU is the final charge amount of power by the power generation amount and the power generation control method during idling charging of the hybrid electric vehicle, wherein the benzalkonium control the battery charge.

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